Specific Process Knowledge/Characterization/III-V ECV-profiler

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III-V ECV-profiler

ECV profiler
ECV cell compartment
Doping profile example. Three n-doped layers and substrate separated by undoped layers

The ECV (Electrochemical Capacitance-Voltage) technique is used to measure carrier-density as a function of depth (doping-profile) on planar semiconductor structures - usually III-V compound semiconductors.

The ECV-profiler is maintained by DTU fotonik (not Danchip) and is therefor not in LabManager!

ECV is a destructive technique requiring a sample size of at least 5x5mm and good skills to obtain reproduceable and reliable results. The sample is placed in a electrochemical cell and electrical contacted to form a capacitor. This is done on one side through the electrolyte and on the other side via a ohmic contact on either the front- or the backside (preferred) of the wafer.

Equipment performance and process related parameters

Performance Excitation
  • halogen white light source for n-type measurements to generate holes for the etching process
Detection
  • between 10^13 to 10^20 carriers/cm^3
Sample size
  • from 5x5mm (10x10mm recommended) up to 2" approximately
Resolution
  • Minimum depth resolution ~1 nm
  • Measurement area:
    • small ring: Ø 1 mm
    • large ring: Ø 3 mm
Carrier density accuracy
  • very dependent on sample. Uncertainty can easily be +-50%.
Materials Allowed substrate materials
  • III-V
  • Silicon